Biology: Cell Types, Reproduction, and Protist Functions

What are the primary structural differences between prokaryotic and eukaryotic cells?

Prokaryotic cells are smaller, lack membrane-bound organelles, and are unicellular. Eukaryotic cells are larger, contain membrane-bound organelles, and can be unicellular or multicellular.

What is lateral gene transfer?

The movement of genes between not closely related species, provides evidence that all species trace back to a common ancestor.

What is the result of meiosis in eukaryotes?

The production of haploid gametes (N).

How do zygotes differ from gametes in terms of ploidy?

Gametes are haploid (N), while zygotes are diploid (2N) following fertilization.

What is binary fission?

A form of asexual reproduction used by prokaryotes where a cell divides into two identical daughter cells.

What are the advantages of sexual reproduction?

Increased genetic diversity, faster evolution, better adaptation to environments, and the reduction of deleterious mutations.

What are the disadvantages of sexual reproduction?

It requires more time and energy, involves courtship, and requires parenting.

What are the advantages of asexual reproduction?

Produces identical offspring, requires no courtship, and is energy-efficient.

What is the Endosymbiosis Theory?

The theory that mitochondria and chloroplasts originated when a host cell took up residence with proteobacteria (mitochondria) or cyanobacteria (chloroplasts).

What evidence supports the Endosymbiosis Theory?

Mitochondria and chloroplasts have circular DNA, undergo binary fission, have their own ribosomes, and are similar in size/shape to bacteria.

What are the characteristics of dinoflagellates?

They are unicellular, have two flagella, can be bioluminescent, and often live symbiotically with coral.

What is the primary function of diatoms?

They act as aquatic primary producers and are characterized by their glass shells.

What role do slime molds play in an ecosystem?

They act as decomposers, primarily for plants.

What is alternation of generations?

A life cycle process in plants and some algae involving a multicellular diploid sporophyte stage and a multicellular haploid gametophyte stage.

How do sporophytes produce spores?

Through the process of meiosis.

What is the ecological importance of protists?

They serve as primary producers (carbon sinks), decomposers, and can cause diseases like malaria or environmental issues like algal blooms.

What is the difference between autotrophic and heterotrophic metabolism?

Autotrophs produce their own energy (often via photosynthesis), while heterotrophs consume other organisms for carbon and energy.

What is nitrogen fixation?

The process of converting inorganic nitrogen (N2) into organic nitrogen.

Why are brown algae considered important for ecosystems?

They are multicellular and provide essential habitats for various animals.

What is the result of mitosis in asexual reproduction?

The production of two identical diploid (2N) cells from a single diploid parent cell.